Compositions and methods for treating depression with combinations of l-3 4-dihydroxyphenylalanine and a hydrazine

ABSTRACT

PHARMACEUTICAL COMPOSITIONS ARE DESCRIBED WHICH CONTAIN, AS THE ACTIVE INGREDIENTS (1) L-3,4-DIHYDROXYPHENYLALANINE AND (2) AN N&#39;&#39;-SUBSTITUTED-N2-(2,3,4-TRIHYDROXYBENZYL)-HYDRAZINE SELECTED FROM THE GROUP CONSISTING OF N&#39;&#39; - DL - SERYL - N2 - (2,3,4 - TRIHYDROXYBENZYL)-HYDRAZINE, N&#39;&#39; - L - SERYL - N2 - (2,3,4-TRIHYDROXYBENZYL)-HYDRAZINE, N&#39;&#39; - GLYCYL - N2 - (2,3,4-TRIHYDROXYBENZYL)-HYDRAZINE AND N&#39;&#39; - TYROSYL - N2-(2,3,4-TRIHYDROXYBENZYL)-HYDRAZINE.

United States Patent 3,646,213 COMPOSITIONS AND METHODS FOR TREATINGDEPRESSION WITH COMBINATIONS F L-3,4-DI- HYDROXYPHENYLALANINE AND AHYDRA- ZINE Giuseppe Bartholini, Basel, Switzerland, assignor toHoiimaun-La Roche Inc., Nutley, NJ.

No Drawing. Continuation of application Ser. No. 753,074, Aug. 16, 1968,now Patent No. 3,557,292. This application Aug. 12, 1970, Ser. No.63,332

Int. Cl. A61k 27/00 US. Cl. 424-319 4 Claims ABSTRACT OF THE DISCLOSUREPharmaceutical compositions are described which con tain, as the activeingredients (1) L-3,4-dihydroxyphenylalanine and (2) an N-substituted-N-(2,3,4-trihydroxybenzyl)-hydrazine selected from the group consistingof N dl seryl N (2,3,4 trihydroxybenzyl)hydrazine, N l seryl N(2,3,4-trihydroxybenzyl) hydrazine, N glycyl N(2,3,4-trihydroxybenzyl)-hydrazine and N tyrosyl N-(2,3,4-trihydroxybenzyl)-hydrazine.

The use of the described compositions, as well as the use of theindividual components thereof separately but as part of the combinedtherapy, in the treatment of depression and to potentiate the activityof antidepressants, such as, imipramine, and other psychoactive drugs ofthe tricyclic type is disclosed.

:RELATED PATENT APPLICATIONS This application is a continuingapplication of my copending application Ser. No. 753,074, filed Aug. 16,1968 now US. Patent No. 3,557,292.

BRIEF SUMMARY OF THE INVENTION The present invention provides a methodfor treating depression and for potentiating the activity ofantidepressants, such as, imipramine, and other psychoactive drugs ofthe tricyclic type.

In a more particular embodiment, the invention provides compositionswhich are useful for the aforesaid purposes.

The invention is carried out by administering L-3,4-dihydroxyphenylalanine, hereinafter referred to as L- DOPA, incombination with an N'-substituted-N -(2,3,4-trihydroxybenzyl)-hydrazine selected from the group consisting ofN'-dl-seryl-N -(2,3,4-trihydroxybenzyl)-hydrazine, N l seryl N (2,3,4trihydroxybenzyl)- hydrazine, N glycyl N (2,3,4 trihydroxybenzyD-hydrazine and N tyrosyl (2,3,4-trihydroxybenzyl)- hydrazine.

DETAILED DESCRIPTION It has been found that in rats, small doses (50mtg/kg.) of N dl seryl N (2,3,4-trihydroxybenzyl)-hydrazinehydrochloride, an inhibitor of the decarboxylase of aromatic aminoacids(DC), enhances, at least for 4 hours, the increase ofL-3,4-dihydroxyphenylalanine (L-DOPA) in blood and brain induced by i.p.or oral administration of this amino acid. Simultaneously, the rise ofcatecholamines (CA) and their metabolites, the phenolcarboxylic acids(PCA) is diminished in the blood and other peripheral tissues (heart,kidney, spleen), but markedly en hanced in the brain. As a consequenceof the reduction of the CA in the periphery, the pheripheral adrenergicstimulation is also reduced. On the other hand, the CA ice stores aretremendously increased in the extrapyramidal brain centers.

These effects are thought to be due to a relatively selective inhibitionof DC by N dl seryl-N -(2,3,4-trihydroxybenzyl)-hydrazine hydrochloridein extracerebral organs. As a consequence of the increased DOPAconcentration in the blood, more of the amino acid penetrates into thebrain where deca rboxylation to CA occurs, sinced the cerebral DC ispractically not inhibited. This selective action of the drug is due to apoor penetration of N -dl seryl N (2,3,4 trihydroxybenzyl)hydrazinehydrochloride into the brain. Thus, the DC activity in the brain ofanimals injected with N d1 seryl N -'(2,3,4-trihydroxybenzyl)-hydrazinehydrochloride is not significantly inhibited up to mg./kg. of the drug,whereas in the heart an 83 percent inhibition can already be observedwith 50 mg./kg.

On the other hand, N -dl-seryl N (2,3,4-trihydroxybenzyl)-hydrazinehydrochloride, when added to tissues homogenate, causes the same degreeof DC inhibition in the brain as in the heart.

Similar results were obtained when, instead of N -dlseryl N (2,3,4trihydroxybenzyl)-hydrazine hydrochloride, one of the followingsubstances was used as decarboxylase inhibitor: N l seryl N -(2,3,4trihydroxybenzyl)-hydrazine hydrochloride; N -glycyl-N -(2, 3,4trihydroxybenzyl)-hydrazine hydrochloride; and N l-tyrostyl N (2,3,4trihydroxybenzyl)-hydrazine hydrochloride.

Further experiments have shOWn that practically only the L-antipode(compound C of the table below) of N seryl N (2,3,4trihydroxybenzyl)-hydrazine hydrochloride is effective. Thus, theD-seryl derivative, in equimolar doses, is 10l3 times less active thanL-seryl compound as inhibitor of the peripheral DC and thus, inincreasing the DOPA induced rise of CA in the brain.

As mentioned above, two other compounds have been found to act by thesame mechanism as N -dl-seryl-N 2,3,4 trihydroxybenzyl) hydrazinehydrochloride, viz.:

N glycyl-N -(2,3,4-trihydroxybenzyl)-hydrazine hydrochloride (compound Bof the table below); and

N 1 tyrosyl N (2,3,4-trihydroxybenzyl)-hydrazine hydrochloride (compoundD of the table below).

The most active is the glycyl compound, which has been shown to bealmost twice as active as the dl-seryl compound and 1 /2 times as activeas the l-seryl compound. Thus, the maximal brain concentration of CA, 1hour after the application of 3 mg./kg. of DOPA by mouth, is obtained by10.78-21.56 mg./kg. p.o. of the glycyl compound.

The tryosyl compound has been shown to be as active as the l-serylcompound.

In the following table, the relative potencies of the differentcompounds are shown as compared to N -dlseryl N-(2,3,4-trihydroxybenzyl)-hydrazine hydrochloride (compound A).

TABLE Comparison of the efiicacy of various compounds in equimolar dosesto 12 mg./kg. of N -d,1-seryl-N -(2,3,4 trihydroxybenzyl)-hydrazinehydrochloride (compound A), on the DOPA-induced increase of brain CA.

Compound A 100 Compound B 179 Compound C 136 Compound D 126 Eachcompound was administered p.o. After 30 minutes, 3 mg./l g. p.o. of2-14C-DOPA was given by mouth and the animals killed 1 hour later. Theeffects of the compounds are expressed as arbitrary units, the efiect ofcompound A being taken as standard (100) In carrying out the invention,an N-substituted-N (2,3,4-trihydroxybenzyl)-hydrazine is administered incombination with L-DOPA. As the hydrazine compound, there can be usedN'-dl-seryl-N -(2,3,4-trihydroxybenzyl -hydrazine, N'- l-seryl-N2,3,4-trihydroxybenzyl -hydrazine, N'-glycyl-N(2,3,4-trihydroxybenzyl)-hydrazine and N-tyrosyl-N-(2,3,4-trihydroxybenzyl) hydrazine. The hydrazine is preferablyemployed in the form of a medicinally acceptable acid addition salt ofthe free base. As used herein the expression medicinally acceptable acidaddition salt denotes salts of the hydrazine free base with medicinallyacceptable acids. Such acids may be inorganic or organic in nature andthey include, for example, hydrochloric acid, sulfuric acid, nitricacid, acetic acid, benzoic acid, citric acid, maleic acid, malic acid,etc.

As indicated heretofore, alternate methods are available for carryingout the present invention. For example, the objectives of the inventioncan be achieved by administering L-DOPA and one of the aforementionedhydrazine compounds separately, the L-DOPA component being administeredpreferably about 30-60 minutes after the administration of thehydrazine. If desired, however, the invention can be practiced byadministering to the patient to be treated a pharmaceutical compositionwhich contains both L-DOPA and the hydrazine compound. Such acomposition should preferably be composed in such a manner that theL-DOPA component is released after, suitably about 30-60 minutes after,the hydrazine component. The dosage of the hydrazine compound and thedosage of L-DOPA used in carrying out the invention is critical.Furthermore, a definite quantitative relationship must be maintainedbetween the active ingredients to insure satisfactory results. However,although critical, each of these factors are variable within certaindefined limits. Thus, for example, in its most comprehensive embodiment,the invention involves the daily administration of from about 200 mg. toabout 1200 mg. of the hydrazine compound, in the form of itshydrochloride, and from about 450 mg. to about 600 mg. of L-DOPA, withthe proviso, however, that at all times there will be provided fromabout 0.5 part by weight to about 3.0 parts by weight, and, preferably,from about 0.5 part by Weight to about 2.0 parts by weight, of thehydrazine compound, for each part by weight of L-DOPA used.

In carrying out the invention, the active ingredients can be embodied inseparate dosage forms, suitable for oral administration, andadministered as such. Suitable oral dosage forms include, for example,soft shell capsules, hard shell capsules, tablets, drages, etc. In thealternative, the active ingredients, in combination, can be embodied ina dosage form suitable for oral administration. For example, soft shellcapsules, hard shell capsules, tablets, drages, etc. which contain amixture of L-DOPA and the hydrazine compound can be prepared and used.Preferred are compositions which are composed in such a manner, that theL-DOPA component is released after, suitably about 30-60 minutes after,the hydrazine component. Additionally, the active ingredients can beprovided in a form suitable for parenteral administration. In such aninstance, it is preferable to administer the active ingredientsseparately rather than as components of a single parenteral composition.In a preferred embodiment, the invention is carried out by administeringa solution of L-DOPA i travenously and a solution of hydrazine, as anacid addition salt, intramuscularly, the L-DOPA solution beingpreferably applied about 30-60 minutes after the application of thehydrazine solution.

The manner in which the various dosage, i.e., administration forms;which are used in the practice of this invention, are prepared will bereadily apparent to persons skilled in the art. Standard techniques andprocedures and conventional excipients and adjuvants are utilized intheir production. In formulating the dosage forms, the activeingredients, either separately or in combination, can be admixed withinert adjuvants and excipients, either inorganic or organic in nature.Such adjuvants and excipients include, for example, water; gelatin;lactose; dicalciumphosphate; stearic acid; calcium stearate; magnesiumstearate; talc; vegetable oils, such as arachis oil; polyalkyleneglycols; preservatives; stabilizers; etc. Mixtures of the activeingredient or ingredients with such excipients and adjnvants can becompressed, for example, into tablets, drages, etc. or they can befilled into suitable capsules. By using appropriate liquid vehicles,solution for parenteral administration can be produced.

The symptoms of depression can be effectively treated by the dailyadministration of from about 200 mg. to about 1200 mg. of the hydrazinecompound in the form of a salt, and from about 450 mg. to about 600 mg.of L-DOPA, with the proviso that, in any instance, there will beprovided from about 0.5 part to about 3.0 parts, preferably, from about0.5 part to about 2.0 parts, by weight of the hydrazine for each part byweight of LDOPA used. Ordinarily, the medication will be administeredthree or four times daily to provide the desired total daily dosage.Thus, for example, the invention can be carried out by administering,three or four times per day, tablets, capsules, etc. containing,separately or in admixture, 150 mg. of the hydrazine compound and 150mg. of L-DOPA. Dosage forms, or a dosage form, providing, for example,300 mg. to 400 mg. of the hydrazine compound and 150 mg. of L-DOPA canbe administered three times per day. Furthermore, dosage forms, or adosage form, providing mg. to mg. of the hydrazine compound and from 150mg. to 200 mg. of LDOPA can be formulated. In carrying out theinvention, one tablet or capsule containing such quantities of theactive medicament can be administered three times per day.

The combination therapy described herein is useful in treatingdepression and potentiating the activity of antidepressants, such as,imipramine, or other such compounds of the type referred to in thepublication New Drugs-Evaluated by A.M.A. Council on Drugs, 1967edition, as psycho-active drugs having a tricyclic structure.

It is to be understood that the specific dosage forms mentionedheretofore are exemplary only and not intended to limit the scope orpractice of the present invention. Within the limits of daily dosageprescribed herein and within the ratio of one active component to theother, set forth heretofore, the amount of the active ingredientsadministered in any given instance may be varied depending upon theneeds and requirements of the patient, as diagnosed by the attendingphysician.

For a full understanding of the nature and objects of this invention,reference may be had to the following examples which are given merely asfurther illustrations of the invention and are not to be construed in alimiting sense. In the examples, all parts given are parts by weightunless otherwise indicated.

EXAMPLE 1 (a) Production of L-DOPA administration form Tablets areproduced in a conventional manner, each of said tablets containing:

Mg. L=DOPA 150 Lactose 200 Corn starch Magnesium stearate 1.5

Talcum 13-5 (1)) Production of N-dl-seryl N(2,3,4-trihydroxybenzyl)-hydrazine hydrochloride administration formTablets are produced in a conventional manner, each of said tabletscontaining;

N -dl-seryl-N -(2,3,4-trihydroxybenzyl) hydrazine hydrochloride 150Mannitol 200 Corn starch 120 Polyvinylpyrrolidone 15 Magnesium stearate1.5 Talcum 13.5

The compositions described in the paragraphs (a) and (b) of this examplewere used, jointly with 50 mg. of imipramine to treat 20 depressedpatients. The combination was administered orally, three times a day. Asa result of this treatment, the imipramine action was considerablyenhanced and the onset of activity was considerably accelerated asevidenced by the fact that activity commenced on the fourth or fifthday, whereas, when imipramine alone is administered, the activitycommences about two weeks after the first administration.

EXAMPLE 2 A hard gelatin capsule, wherein the L-DOPA component ispresent in a late-release form, is produced as follows:

A core consisting of 50 mg. L-DOPA, 8 mg. corn starch, 15 mg. lactose,1.8 mg. talcum and 0.2 mg. magnesium stearate is coated with acelluloseacetatephthalate lacquer in order to make it resistant to thegastric juices.

A granulate is prepared which consists of 114.2 mg. of N dl-seryl N(2,3,4-trihydroxybenzyl)-hydrazine hydrochloride, 5 8.25 mg. mannitoland 23.7 mg. polyvinylpyrrolidone.

The coated core and the granulate are incorporated into a hard gelatincapsule. This composition will release the L-DOPA component about 30-60minutes after the hydrazine component.

In the paragraphs which follow hereinafter, there is described, in anexemplary manner, the methods of preparing (a), N -1-seryl-N -(2,3,4trihydroxybenzyl)-hydrazine; (b) N -glycyl-N (2,3,4 trihydroxybenzyl)-hydrazine; and (c) N -1-tyrosyl-N -(2,3,4 trihydroxybenzyl)-hydrazine.Such descriptions are included herein for the sake of completedisclosure, it being understood that neither the compounds nor themethods for their production are part of the present invention.

(a) 15.4 g. of 2,3,4 trihydroxy-benzaldehyde are dissolved in 200 ml. ofboiling water, whereupon 15.2 g. of l-seryl hydrazine hydrochloride areadded to and dissolved in the resulting solution. The solution is thenevaporated under reduced pressure and the water is displaced by addingethanol in small portions. The resulting crystals are separated from themother liquor by filtration and washed with ethanol and ether. Theresulting N l seryl-N -(2,3,4-trihydroxybenzylidene)-hydrazinehydrochloride melts at 260265. [a] =+23 (c.=1 in Water).

21 g. of the above benzylidene compound are suspended in 300 ml. ofmethanol and the resulting suspension is hydrogenated by means of apalladium-on-carbon catalyst. After a hydrogen consumption of 1700 ml.,the catalyst is removed by filtration, the filtrate is concentratedunder reduced pressure, the resulting viscous residue is dissolved in asmall quantity of ethanol and diluted with about 600700 ml. aceticester, whereafter an amorphous precipitate is formed. This precipitateis separated from the mother liquor by filtration, washed with aceticester and ether and dried under reduced pressure over phosphoruspentoxide. The N -l-seryl N (2,3,4-trihydroxybenzyl)-hydrazinehydrochloride so obtained is an amorphous substance, which is readilysoluble in water and which is decomposed with elfervescence at about [a]=l0 (c. =1 in water); +18 (c.=1, in dimethylformamide).

(b) 15.4 g. of 2,3,4 trihydroxy-benzaldehyde are dissolved in 200 ml. ofboiling water, whereupon 15.2 g. of glycyl-hydrazine hydrochloride areadded to the resulting solution. After a few minutes the solutionbecomes turbid and soon solidifies forming a crystalline mass. This massis cooled in ice-water, filtered and washed with a small quantity ofwater and a relatively great quantity of acetone. The resulting N-glycyl-N (2,3,4 trihydroxybenzylidene)-hydrazine hydrochloride formsWhite to yellowish crystals melting at 303305 with decomposition.

24 g. of the N -glycyl-N -(2,3,4 trihydroxybenzylidene)-hydrazinehydrochloride are suspended in 300 ml. of water and hydrogenated over apalladium-on-carbon catalyst. All of the hydrazide is dissolved when 2.5liters of hydrogen are consumed. The catalyst is removed by filtration,the filtrate is concentrated to a volume of 40- 50 ml. and diluted with200 ml. of absolute ethanol. Crystallization takes place within a fewseconds. The crystalline material is allowed to stand in a refrigeratorovernight, filtered, dissolved in 40 ml. of water at a temperature nothigher than 40-50" and crystallization is initiated by adding 120 ml. ofmethanol. The resulting N -glycyl-N -(2,3,4 trihydroxybenzyl)-hydrazinehydrochloride forms white crystals which dissolve in water forming asolution of neutral reaction, and which melt at 179182.

(c) 19.2 g. of 1-tyrosyl-hydrazine are dissolved in 300 ml. of methanoland 7 ml. of glacial acetic acid, whereupon 15.4 g. 2,3,4trihydroxy-benzaldehyde are added to the resulting solution. Thereaction mixture is hydrogenated by means of a palladium-on-carboncatalyst, the calculated quantity of 2.4 liters of hydrogen beingconsumed in about 1 week. 12.1 ml. of benzyl chloride are then added andhydrogenation is continued until hydrogen consumption is completed. Thefiltrate obtained upon removal of the catalyst is concentrated underreduced pressure and the reaction product is precipitated by theaddition of acetic ester. The N -1-tyrosyl-N -(2,3,4-trihydroxybenzyl)-hydrazine hydrochloride thus obtained is a greenishpowder which is readily soluble in water and which decomposes witheffervescence at about 120. [a] =+15 (c.=l,in water).

The racemic N -tyrosyl-N -(2,3,4 trihydroxybenzyl)- hydrazinehydrochloride can be obtained in a manner analogous to that set forthabove, using racemic tyrosyl hydrazine as starting material.

What is claimed is:

1. A method of treating depression which comprises administering to adepressed patient an effective dosage of (a) L-3,4dihydroxyphenylalanine and (b) a hydrazine compound selected from thegroup consisting of N'- dl seryl N (2,3,4-trihydroxybenzyl)-hydrazine,N- l seryl N (2,3,4-trihydroxybenzyl)-hydrazine, N'- glycyl N (2,3,4trihydroxybenzyl)-hydrazine, N'- tyrosyl-N (2,3,4trihydroxybenzyl)-hydrazine and a medicinally acceptable acid additionsalt of such,compounds, the compounds (a) and (b) being used in suchquantities as to maintain a ratio of from about 0.5 part to about 3.0parts by weight of said (b) for each part by weight of said (a).

2. The method of claim 1 wherein the compound (a) is administered about30-60 minutes after the administration of the compound (b).

3. A method of potentiating the antidepressant activity of tricyclicantidepressants which comprises administering daily to a patient,exhibiting the symptoms of depression, mg. of imipramine in combinationwith (a) 450 mg. to about 600 mg. of L-3,4 dihydroxyphenylalanine and(b) 200 mg. to about 1200 mg. of a hydrazine compound selected from thegroup consisting of N'-dl-se1'y1-N (2,3,4-trihydroxybenzyl)-hydrazine,N'-I-sery1-N -(2,3,4- trihydroxybenzyl)-hydrazine, N'-g1ycy1-N (2,3,4trihydroxybenzy1)-hydrazine, N'-ty1'osyl-N -(2,3,4trihydroxybenzyD-hydrazine and a medicinally acceptable acid additionsalt of such compound, the compounds (a) and (b) being used in suchquantities as to maintain a ratio of from about 0.5 part to about 3.0parts by weight of said (b) for each part by Weight of said (a).

4. The method of claim 3 wherein the compound (a) is administered about30-60 minutes after the administration of the compound (b).

8 References Cited Chem. Abst. v01. 659600 0 (1966).

STANLEY J. FRIEDMAN, Primary Examiner US. Cl. X.R.

